With rapid development of the display technology, touch screen panel has been popular in people's lives. At present, an existing in-cell touch screen panel detects finger's touch position by adopting a mutual capacitive or self capacitive principle. Compared to the mutual capacitive touch screen panel, the self capacitive touch screen panel has a high signal noise ratio and low cost in necessary devices.
The self capacitive touch screen panel in the prior art will be described in detail below in conjunction with drawings. FIG. 1 is a diagram of a self capacitive touch screen panel, in which a self capacitive electrode is provided in an array substrate, in the prior art, as shown in FIG. 1, a plurality of self capacitive electrodes, which are provided in the same layer and insulated from each other, are provided on the array substrate, each self capacitive electrode is connected to a touch detection chip through a separated lead. The lead includes a surrounding wire provided in a border region of the array substrate and a wire, one end of which is connected to the self capacitive electrode and the other end of which is connected to the surrounding wire. Certainly, in the prior art, all the self capacitive electrodes may also be provided in the assembling substrate.
A working principle of the self capacitive touch screen panel is as follows: when a human body does not touch the screen panel, each self capacitive electrode bears a capacitance of a fixed value, and when the human body touches the screen panel, the corresponding self capacitive electrode bears the capacitance of the fixed value plus a body capacitance, then a touch position may be determined by the touch detection chip through detecting variations in capacitance values of the respective self capacitive electrodes during the touch period.
However, since the number of the self capacitive electrodes is large, the number of corresponding leads is large, taking the case that each self capacitive electrode occupies an area of 5 mm*5 mm as an example, a 5 inch liquid crystal display panel needs more than 260 self capacitive electrodes, the large number of self capacitive electrodes result in increase of wires in a channel in the touch screen panel, and thus a touch blind zone (which refers to a region in which wires are crowded, and signals in the region are relatively chaotic, thus touch performance cannot be ensured) is caused. In addition, during designing, in order to reduce the number of films, wires in the leads are generally provided in the same layer as the self capacitive electrodes, each self capacitive electrode needs a separated wire to lead it to the frame region, and surrounding wires in one-to-one correspondence with the wires are provided in the frame region. Since the number of the self capacitive electrodes is large, thus the number of corresponding surrounding wires on the array substrate or the assembling substrate is large, which may cause the frame region of the touch screen panel to be broader, and is adverse to the narrow frame design.